Effect of Packaging Material on Shelf Life and Quality of Ware Potato Tubers Stored at Ambient Tropical Temperatures

The effect of seven packaging materials (transparent perforated and non-perforated high-density polyethylene (HDPE) bags, black perforated and non-perforated low-density polyethylene (LDPE) bags, nylon gunny sacks, khaki bags and net bags) on post-harvest quality of tubers from three potato cultivars was evaluated. Data were collected on time and percentage of sprouting, weight loss rates and percentage tubers with greening and rotting. Packaging significantly reduced weight loss and rate of tuber greening but increased the rate of sprouting and decay incidences. Non-perforated PE bags were the most effective in reducing weight losses, recording losses of 0.7 to 0.9% after 32 days in storage while unpackaged tubers had weight losses of 11 to 12%. Tuber rotting was highest (60 to 66% of the tubers) in non-perforated PE bags. Greening was faster in non-packaged tubers recording 55 to 100% after 2 weeks in storage and showed high cultivar differences, but did not occur in black bags, whether perforated or non-perforated. Sprouting was complete by week 3 in all tubers packaged in non-perforated HDPE bags irrespective of cultivar. Although the non-perforated HDPE bag packaging prevented weight loss, its positive effect was counteracted by the high incidence of rotting and sprouting. Amongst the different materials evaluated, perforated low-density black PE bags were the best method for ware potato packaging due to low sprouting, reduced weight loss, low rate of tuber greening and reduced rate of tuber decay compared to other packaging materials. The study also indicated that the interaction between cultivars, packaging and storage period also affected shelf life of ware potatoes under ambient tropical conditions.     

Bioavailability of riboflavin from fortified palm juice

The bioavailability of riboflavin from fortified palm juice was assessed in young adult men, Riboflavin status was assessed from urinary riboflavin excretion and erythrocyte glutathione reductase activity coefficient (EGR-AC) while iron status was assessed from haemoglobin and serum ferritin concentrations. Although the consumption of unfortified palm juice made significant contribution to the meager riboflavin intake, it conferred no metabolic advantage. The consumption of fortified palm juice produced a marked reduction in EGR-AC values and a significant increase in urinary riboflavin excretion. Since iron release from storage sites may be flavin dependent, riboflavin deficiency may affect iron utilization. Fortification may prove effective in alleviating nutrient deficiencies, but the carrier vehicle must be acceptable to all age groups.     

Environmental variables affect the hard-to-cook phenomenon of cowpea (Vigna unguiculata) seed

Changes in moisture content and cooking rate of cowpea (Vigna unguiculata) seeds which were sun-dried for 5 hours on cement, wood, or corrugated iron sheet surfaces and packaged for 6 months in jute or polythene bags were studied. Relationships and effects of interacting variables studied were examined using the contrast analysis technique. From day zero to about 2 months of storage, the sun-dried samples had significantly (p<0.01) lower moisture content and longer cooking times than the corresponding control samples. However, moisture-gain and cooking time increased progressively throughout the storage period for all samples studied. The relationship between these two variables, tested at p=0.01 using contrast analysis technique, was dependent on the choice of packaging material.     

Effect of domestic processing on total and extractable calcium and zinc content of Bathua ( Chenopodium album) and Fenugreek (Trigonella foenum graecum) leaves

Bathua (Chenopodium album) and fenugreek (Trigonella foenum graecum) stored in polyethylene bags and without packaging for 24 or 48 hours in a refrigerator at 5 or 30 ^°C in polyethylene bags. The fresh leaves were also dried (oven and sun); blanched (5, 10 or 15 min) and cooked in an open pan and a pressure cooker. The processed leaves were analyzed for total and extractable calcium and zinc content. The Ca and Zn content of these leaves varied from 970 to 2230 and 10.50 to 12.30 mg/100 g DM and the percentage HCl-extractability was 80.34 to 83.04 and 82.43 to 83.90, respectively. Non significant effects of drying and storage were observed on total Ca and Zn content and HCl-extractability while blanching and cooking resulted in significant improvement of HCl-extractability of these two minerals. Thus, cooking and blanching are good ways to improve the HCl-extractability of Ca and Zn.     

Technological aspects of keeping and pickling qualities of cucumbers as influenced by fertilizers

The effect of the interactions between K (potassium) and Ca (calcium) applications (preharvest treatment), packaging method and storage conditions on the keeping and pickling qualities of cucumber were investigated. Spraying with 100 ppm K and 5000 ppm Ca prolonged the shelf-life of cucumber, especially when packaged in perforated polyethylene and stored at refrigeration conditions. Packaging and refrigeration both reduced weight loss and decay percentages. Decay was greater in packaged fruits stored at high temperature. Packaging had only a slight effect on chemical composition. Packaged fruits from plants sprayed with 100 ppm K maintained their fresh appearance and firmness 3 times longer than a control sample at ambient conditions and over 20 days under refrigeration. Sensory evaluation of pickled cucumbers revealed that both K and Ca applications on plants during growth improved substantially the pickling quality of cucumber.     

Bioavailability to rats of iron from fortified grain amaranth

In this study, fortified and unfortified grain amaranth seed flour diets and a FeSO₄-fortified casein diet (used as a control) were evaluated for their iron (Fe) bioavailability. NaFeEDTA, ferrous fumarate, and FeSO₄-fortified grain amaranth were fed to growing Sprague-Dawley weaning male rats. Iron intake, hemoglobin iron (HbFe) gain, Fe availability, total iron binding capacity (TIBC), serum iron, non-haem liver iron and red bloodcell volume (RBV) were determined, and the values were compared with those of the FeSO₄-fortified casein diet control. Ferrous fumarate fortified diets gave consistently high values for all these parameters, compared with consistently low values for the amaranth diet without iron fortification.Relative biological values (RBVs) were 0.40, 1.55, 1.75, 1.67 and 1.00 for animals fed on an unfortified amaranth diet, and diets fortified with NaFeEDTA, ferrous fumarate, FeSO₄ and casein fortified with FeSO₄, respectively. Using FeSO₄-fortified casein as control, ferrous fumarate gave a superior RBVs (1.75 vs. 1.00). The RBVs, of the unfortified cereal diets were 40% that of the control, perhaps suggesting low iron absorption from the amaranth cereal. Based on the results of this study, amaranth cereal can be considered an ideal food vehicle for iron fortification. The iron fortification of choice is ferrous fumarate.     

Effect of home processing on total and extractable calcium and zinc content of spinach (Spinach oleracia) and amaranth (Amaranthus tricolor) leaves

Spinach (Spinacia oleracia) and amaranth (Amaranthus tricolor) leaves were stored in polyethylene bags and without packing for 24 and 48 hours in a refrigerator at 5 and 30 °C in polyethylene bags. The fresh leaves were also dried (oven and sun); blanched (5, 10 and 15 min) and cooked in an open pan and a pressure cooker. The processed leaves were analysed for total and extractable calcium and zinc content. The Ca and Zn content of these leaves varied from 1320 to 2120 and 11.70 to 12.60 mg/100 g DM and the percentage HCl-extractability was 77.82 to 81.92 and 85.16 to 86.15, respectively. No significant effects of drying and storage were observed on total Ca and Zn content and HCl-extractability while blanching and cooking resulted in significant improvement of HCl-extractibility of these two minerals. Thus, cooking and blanching are good ways to improve the HCl-extractibility of Ca and Zn.     

钙处理对红江橙采后生理的影响

研究不同浓度的CaCl_2溶液处理后对聚乙烯薄膜袋包装、室温(25±1)℃下贮藏的红江橙部分生理变化的影响.结果表明,低浓度钙(<4.0%CaCl2)对红江橙的生理变化影响不明显.高浓度钙(6.O%,8.0%CaCl_2)能显著刺激红江橙的生理变化,导致果实腐烂增加.适当浓度钙(4.0%CaCl_2)溶液处理能有效降低红江橙的呼吸强度、减少乙烯释放量:有效抑制过氧化物酶(POD)活性、减缓过氧化氢酶(CAT)活性降低的趋势、抑制组织MDA含量和果皮电导率的升高,减轻了膜脂过氧化作用:还有效抑制了多聚半乳糖醛酸酶(PG)活性、减缓了果实的软化速度,56 d时果实的腐烂率仅为3.1%,比对照的低39.6%(p<0.01).     

Use of Banana (<Emphasis Type="Italic">Musa acuminata</Emphasis> Colla AAA) Peel Extract as an Antioxidant Source in Orange Juices

Using banana peel extract as an antioxidant in freshly squeezed orange juices and juices from concentrate was evaluated. Free radical scavenging capacity increased by adding banana peel extracts to both types of orange juice. In addition, remarkable increases in antioxidant capacity using 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical were observed when equal or greater than 5 mg of banana peel extract per ml of freshly squeezed juice was added. No clear effects were observed in the capacity to inhibit lipid peroxidation. Adding 5 mg banana peel extract per ml of orange juice did not substantially modify the physicochemical and sensory characteristics of either type of juice. However, undesirable changes in the sensory characteristics (in-mouth sensations and colour) were detected when equal or greater than 10 mg banana peel extract per ml of orange juice was added. These results confirm that banana peel is a promising natural additive that increases the capacity to scavenge free radicals of orange juice with acceptable sensory and physicochemical characteristics for the consumer.     

Effect of thermal packaging temperature on Chinese steamed bread quality during room temperature storage

In order to investigate the influence of different packaging temperature on thermal-vacuum packaged Chinese steamed bread (CSB) quality under room temperature storage, the packaging temperatures of 50 °C, 70 °C and 90 °C were set respectively to study the effect on the packaging vacuum degree (VD) and starch retrogradation properties. The VD and moisture content of thermal-vacuum packaged CSB significantly increased with the increase of the packaging temperature from 50 °C to 90 °C, while the hardness of CSB decreased, and there was no significant difference in moisture migration during room temperature storage. The results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and small angle X-ray scattering (SAXS) indicated that CSB packaged at different temperatures formed B-type crystals, leading to an enhanced the ordered and dense state of starch structure, and the semi-crystalline growth ring structure disappeared during storage. The influence of different packaging temperatures on VD of CSB could effectively hinder the formation of ordered and dense state of CSB starch, consequently delaying the crystallization of amylopectin and inhibiting the progress of staling. The result of this study is of great significance for improving the quality of starchy foods and guiding the industrial development of Chinese steamed bread.     

不同浓度壳聚糖处理对采后西番莲果实耐贮性和贮藏品质的影响

为研究不同浓度壳聚糖处理对采后西番莲果实耐贮性和贮藏品质的影响,选取采后‘福建百香果1号’西番莲果实,用稀释50倍、100倍、150倍、200倍、250倍的卡多赞（壳聚糖）溶液浸泡5 min,以用蒸馏水浸泡5 min为对照,果实浸泡后取出晾干,之后用0.015 mm厚的聚乙烯薄膜袋密封包装（每袋装果10个）,置于28℃和相对湿度80%条件下贮藏,贮藏期间每隔3 d取样,用于测定西番莲果实的耐贮性和贮藏品质指标。结果表明：与对照西番莲果实相比,壳聚糖处理能有效降低采后西番莲果实的呼吸强度,延缓果皮细胞膜透性的上升,降低果实失重率,保持较高的果实商品率;此外,壳聚糖处理能保持较高的外果皮L ^*、a ^*、b ^*值及果皮花色素苷、类黄酮和总酚含量,维持较高的果肉可溶性固形物、可滴定酸、可溶性总糖、蔗糖、维生素C和类胡萝卜素含量。因此,壳聚糖处理能增强采后西番莲果实的耐贮性和维持较高的贮藏品质;其中,以稀释200倍的卡多赞溶液处理的保鲜效果最佳,可作为提高西番莲果实采后耐贮性、延长其保鲜期的适宜处理条件。     

Chemical composition and organoleptic evaluation of juice from steamed cashew apple blended with orange juice

Fully riped cashew apples (yellow variety) were steamed for 7 minutes prior to juice extraction. The extracted juice was blended with various proportions of sweet orange juice. Chemical composition and organoleptic evaluation were carried out on both the blended and unblended juices. The ascorbic acid content of unsteamed cashew apple juice was 287 mg/100 ml. Steaming of the cashew apple prior to juice extraction resulted in a decreased (230 mg/100 ml) content of ascorbic acid. It also led to slight decreases in soluble solids and titratable acidity. A comparison of the chemical composition of the two juices showed that the orange juice contained more sugars, titratable acidity and soluble solids but less ascorbic acid than cashew apple juice. Consequently, the soluble solids, titratable acidity, reducing and total sugars of the blends increased with increase in the proportions of orange juice while the content of ascorbic acid was decreasing. In spite of the decrease in ascorbic acid content of the blends, results showed that blended juice would no doubt be a very good source of ascorbic acid. Result of the organoleptic evaluation revealed that a 60% cashew apple and 40% orange juice gave a good quality juice in terms of flavor, after taste and overall acceptability.     

Changes in β-carotene and ascorbic acid content of fresh amaranth and fenugreek leaves during storage by low cost technique

Leafy vegetables are highly perishable and their shelf life depends on duration and conditions of storage. A low cost storage structure was used to extend the shelf life of amaranth and fenugreek and their quality was evaluated on the basis of retention of -carotene, ascorbic acid and chlorophyll during storage. Losses of -carotene ranged from 46.5 to 85.0% for amaranth and 24.0 to 73.0% for fenugreek depending on duration and conditions of storage. Similarly ascorbic acid retention varied from 9–32% for amaranth and 23–80% for fenugreek. Results showed that the degradation of quality parameters was faster at ambient conditions and packaging of leaves in low density polyethylene bags was beneficial in improving shelf life and nutritive value. Low cost storage structure was similar to low temperature storage for retention of -carotene, ascorbic acid, chlorophyll content and enhancement of shelf life.     

Display practices and changes in riboflavin content of non-fermenting palm juice

Changes in riboflavin content of industrially bottled palm juice stored at different light intensities similar to display patterns practised by traders was studied. The loss of riboflavin in the first 24 hours was significantly higher than in the second 24 hours in both transparent (P<0.001) and green bottles (P<0.02) exposed to bright sunlight. Riboflavin loss from samples stored in transparent bottles occurred at a faster rate (24–71% of initial) than from samples in green bottles (0–29%) over a 36-hour period. Further loss of riboflavin did not occur over the next 36 hours due to cool weather conditions. In contrast, only 6% of initial riboflavin was lost after 72 hours of continuous exposure to fluorescent light: this increased by 53% by the ninth week. The data showed that riboflavin loss from bottled palm juice varied with the container, the environmental conditions and period of storage. It is recommended that palm juice should be displayed in dark bottles and protected from bright light.     

不同保鲜薄膜袋包装对‘松风本’龙眼果实低温贮藏效果的影响

以福建省晚熟龙眼品种‘松风本’龙眼果实为材料,研究微孔复合保鲜薄膜袋、高密度聚乙烯薄膜袋、普通聚乙烯薄膜袋等3种保鲜薄膜袋包装对龙眼果实在（5±1）℃下低温贮藏效果的影响。结果表明：微孔复合保鲜薄膜袋内较高的O2含量可明显改善龙眼果实外观品质,保持较高的龙眼果肉可溶性固形物、可滴定酸和维生素C等营养物质含量;高密度聚乙烯薄膜袋内较高的CO2含量能延缓龙眼果肉自溶和果实病害发生,但果肉乙醇含量积累会影响龙眼果实品质,加速龙眼果实果皮褐变;普通聚乙烯薄膜袋内的O2含量最低而CO2含量最高,会导致果肉乙醇含量积累过多、果实发病率最高和好果率最低。综合结果可知,3种保鲜薄膜袋包装对‘松风本’龙眼果实在（5±1）℃低温下贮藏保鲜效果为微孔复合保鲜薄膜袋＞高密度聚乙烯薄膜袋＞普通聚乙烯薄膜袋。     

Increased Antioxidant Content in Juice Enriched with Dried Extract of Pomegranate (Punica granatum) Peel

Antioxidants are compounds responsible for free radical scavenging in the body. They protect the organism from oxidative modification of cells and tissues. These modifications have been associated with degenerative diseases, atherosclerosis and carcinogenesis. Punica granatum displays high antioxidant potential due to the presence of phenolic compounds, which are capable of disease prevention. The present study showed the highest antioxidant activity in pomegranate peel than in seeds and pulp. Based on these results, pomegranate peel was used to produce dried extract that was added to commercial tomato juice and orange juice with strawberries. Analysis to determine the content of phenolic compounds and antioxidant activity was performed on pomegranate pulp, seeds and peel and in juices enriched with dried extract of pomegranate peel. The dried extract was responsible for a significant increase in antioxidant activity of the juices, proportional to the concentrations added. However, although both flavors of enriched juices displayed high antioxidant levels, the samples with higher dried extract concentrations received the lowest scores from sensory analysis participants due to the characteristic astringent flavor of pomegranate peels. Therefore, to obtain greater acceptance in the consumer market, we concluded that the maximum addition of dried pomegranate peel extract is 0.5% in tomato juice and orange juice with strawberries.     

低温贮藏对‘松风本’龙眼果实品质和耐贮性的影响

本文以‘松风本’龙眼果实为试验材料,研究贮藏温度对龙眼果实贮藏品质和耐贮性的影响。采后龙眼果实经过挑选、清洗等预处理后晾干,用聚乙烯保鲜袋（0.015 mm厚）包装,分别置于室温(25±0.5)℃和低温(3±0.5)℃下贮藏。贮藏期间定期取样测定龙眼果实的营养品质和耐贮性指标。结果表明：与(25±0.5)℃室温贮藏相比,(3±0.5)℃低温贮藏可以有效延缓龙眼果实采后呼吸强度,保持较高的果皮色素（叶绿素、类胡萝卜素、花色素苷、类黄酮）含量和果肉营养物质（可溶性固形物、可溶性总糖、蔗糖、还原糖、维生素C）含量。此外,(3±0.5)℃低温贮藏还能延缓采后龙眼果肉自溶和果皮褐变,以及抑制龙眼果实失重率的升高,维持较高的龙眼果实商品率。据此认为,(3±0.5)℃可以作为‘松风本’龙眼果实低温贮运的推荐温度条件,以保持‘松风本’龙眼果实的贮藏品质和延长其保鲜期。     

不同品种菠萝原果汁品质分析及其加工适应性

以4个菠萝品种果实为材料,研究其原果汁品质及加工适应性、耐贮性的差异。结果表明,粤脆原果汁品质指标最优,其次是粤引澳卡,巴厘和无刺卡因品质相对较差;4个品种原果汁的色泽均为橙黄色至柠檬黄色;粤脆原果汁的总氨基酸含量最高,其次是巴厘和粤引澳卡,无刺卡因的最低。果汁均质处理对粤脆加工菠萝汁维生素C影响最大,其次是巴厘和无刺卡因,对粤引澳卡影响最小;热脱气对无刺卡因维生素C含量影响最大,其次是粤引澳卡和巴厘,对粤脆影响最小。在贮藏过程中4个品种的加工菠萝汁粘度、酸度变化小;但贮藏期间维生素C的变化有差异,第84天时,粤脆及巴厘2个品种的维生素C含量保持率在50%以上,而粤引澳卡及无刺卡因的趋于0;氨基酸态氮含量呈缓慢递减的趋势,保持率最高的是粤脆;L*值(亮度值)降低,a*值(红色源)升高,b*值(黄色源)降低,色泽均变浅,但粤脆变化最小,其次为巴厘和无刺卡因,粤引澳卡变化较大。     

Production and storage stability of non alcoholic banana beverage powder

Powder for an instant, non-alcoholic beverage formulation was manufactured by sundrying and ovendrying of a popular dessert (silk) banana variety. The reconstituted beverage was organoleptically acceptable. The effect of traditional sundrying on mats and ovendrying methods on product quality was investigated. Sundrying resulted in losses of Vitamin A, C and total sugar contents by 74, 91 and 63%, while ovendrying losses were 73, 90 and 62%, respectively. Nutrient losses during storage for three months in transparent polythene bags reached 93, 93 and 70% in sundried samples and 84, 99 and 55% in ovendried samples, respectively. The moisture content of sundried and ovendried samples increased by 12 and 17%, respectively, during storage. The increase in microbial load in this period was higher in sundried samples.     

Production and storage stability of non-alcoholic pawpaw beverage powder

Powder for instant non-alcoholic pawpaw beverage formulation was manufactured by traditional sundrying and controlled ovendrying. The reconstituted beverage was organoleptically acceptable. The effect of sundrying on mats and ovendrying on product quality was investigated. Sundrying resulted into losses of vitamins A and C, and total sugar by 97, 98 and 87 percent; while, oven drying losses were 92, 98 and 87 percent, respectively. Nutrient losses during storage in transparent polythene bags at ambient conditions reached 98, 98 and 82 percent in sundried samples and; 87, 99 and 67 percent in ovendried samples respectively. The moisture content of sundried and oven dried samples increased by 14 percent during storage. The increase in microbial load during storage was higher in sundried samples.